Nokea
How are the motor pathways of the ANS arranged?
- A. Single neuron from CNS to target organ
- B. Two neurons, a pre-ganglionic and post-ganglionic neuron
- C. Multiple neurons from CNS to target organ
- D. Single neuron from CNS to peripheral ganglia
Correct Answer: B
Rationale: The correct answer is B. The motor pathways of the autonomic nervous system (ANS) are organized with two neurons: a pre-ganglionic neuron that transmits the signal from the central nervous system (CNS) to a ganglion, and a post-ganglionic neuron that conveys the signal from the ganglion to the target organ. This dual-neuron pathway enables the integration and modulation of signals before reaching the target organ, allowing for a more sophisticated and adaptable control system. Choice A is incorrect as it describes a single neuron pathway, which is not characteristic of ANS motor pathways. Choice C is incorrect as it suggests multiple neurons from the CNS to the target organ, which is not the typical arrangement. Choice D is incorrect as it describes a single neuron pathway from the CNS to peripheral ganglia, which does not account for the ganglionic transmission in ANS motor pathways.
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Which of the following best describes eosinophils?
- A. A type of granulocyte that secretes histamine to stimulate the inflammatory response.
- B. The most abundant type of white blood cell that secretes substances toxic to pathogens.
- C. A type of granulocyte found under mucous membranes that defends against multicellular parasites.
- D. A circulating granulocyte with high phagocytic activity and aggressiveness.
Correct Answer: C
Rationale: Eosinophils are best described as a type of granulocyte found under mucous membranes that defends against multicellular parasites. They release toxic substances to combat parasitic infections and play a significant role in allergic reactions and asthma. Histamine secretion to stimulate inflammation is more characteristic of basophils, while high phagocytic activity and aggressiveness are features of neutrophils, not eosinophils. Describing eosinophils as the most abundant type of white blood cell that secretes toxic substances to pathogens is inaccurate since eosinophils specifically target multicellular parasites, not a broad range of pathogens.
What are the three types of capillaries?
- A. Continuous, fenestrated, sinusoidal
- B. Continuous, discontinuous, fenestrated
- C. Sinusoidal, alveolar, continuous
- D. Continuous, fenestrated, vascular
Correct Answer: A
Rationale: The correct answer is A: Continuous, fenestrated, sinusoidal. Capillaries are classified into three types based on their permeability: continuous (least permeable), fenestrated (moderately permeable), and sinusoidal (most permeable). Choices B, C, and D are incorrect because they do not represent the three main types of capillaries. Choice B includes 'discontinuous' which is not a recognized type. Choice C includes 'alveolar' which is not a type of capillary, and Choice D includes 'vascular' which is too broad and not specific to capillary classification.
Which type of capillary is the most permeable?
- A. Continuous capillaries
- B. Sinusoidal capillaries
- C. Fenestrated capillaries
- D. Vascular capillaries
Correct Answer: B
Rationale: Sinusoidal capillaries are indeed the most permeable type. They are characterized by large gaps between endothelial cells, allowing for the passage of large molecules and cells. These capillaries are commonly found in organs like the liver, bone marrow, and spleen where high permeability is required for specialized functions such as filtration and exchange of substances.
Continuous capillaries have tight junctions and are the least permeable, found in muscles, lungs, and the central nervous system where strict control over permeability is needed. Fenestrated capillaries, on the other hand, have small pores or fenestrations and are intermediate in permeability, found in organs like the kidneys, endocrine glands, and intestines where selective permeability is necessary. Vascular capillaries is not a specific type of capillary and is not a valid choice.
What are the primary differences between systemic and pulmonary circulation?
- A. Systemic circulation is shorter and has lower blood pressure
- B. Pulmonary circulation is shorter and has higher blood pressure
- C. Systemic circulation is longer and has higher blood pressure
- D. Systemic circulation is shorter but has higher blood pressure
Correct Answer: C
Rationale: The correct answer is C. Systemic circulation is longer as it involves carrying oxygenated blood throughout the body, requiring higher blood pressure. Pulmonary circulation is shorter and involves the flow of blood only through the lungs, hence having lower blood pressure. Therefore, systemic circulation is longer and has higher blood pressure compared to pulmonary circulation. Choice A is incorrect as systemic circulation is longer, not shorter, and has higher blood pressure. Choice B is incorrect as pulmonary circulation has lower blood pressure, not higher. Choice D is incorrect as systemic circulation is longer, not shorter, despite having higher blood pressure.
Which three parts make up the large intestine?
- A. Duodenum, ileum, jejunum
- B. Cecum, colon, rectum
- C. Ileum, jejunum, rectum
- D. Colon, cecum, ileum
Correct Answer: B
Rationale: The correct answer is B: Cecum, colon, rectum. The large intestine is composed of the cecum, colon, and rectum. These parts are responsible for water absorption and feces formation. Choices A, C, and D are incorrect. A contains parts of the small intestine (duodenum, ileum, jejunum), C has a mix of small and large intestine parts, and D includes the small intestine part ileum. Understanding the correct anatomy of the large intestine is essential for distinguishing it from the small intestine.